Unconventional spin glass behavior in the cubic pyrochlore Mn ₂Sb₂O₇

The new pyrochlore Mn₂Sb₂O₇ has been synthesized via a low-temperature method to retain cubic Fd3m symmetry. symmetry. The resulting material has an unconventional spin glass state at T_SG ∼41 K, in the absence of detectable site disorder or a structural phase transition. A peak in the DC susceptibility at T_SG, and a characteristic shift in the real part of the AC susceptibility was noted, but with a slightly more dynamic state than predicted through the typical Mydosh spin glass parameter of ΔT_SG/[T_SGlog(ω)]. Time-dependent magnetization measurements show glassy behavior below 41 K. Elastic neutron scattering measurements on powder samples show significant magnetic diffuse scattering from the Mn spins beneath the transition, similar to the scattering observed in the spin liquid Tb₂Ti₂O ₇. The dynamic character of Mn₂Sb₂O₇ is inferred to arise from the frustration inherent within the pyrochlore lattice.